Why Wildfire Risk Can Vary from One Home to the Next

Mercury Insurance explains why nearby homes can face very different wildfire risk.

LOS ANGELES, July 23, 2026 /PRNewswire/ -- As California enters the heart of wildfire season, Mercury Insurance (NYSE/NYSE TX: MCY) says homeowners often ask the same question after major fires: How can one house survive while another nearby is destroyed? According to wildfire experts, the answer is rarely chance.

Wildfire behavior is shaped by a complex interaction of weather, terrain, vegetation, construction and wind-driven embers that can vary dramatically across a single neighborhood. Understanding those localized conditions can help homeowners better appreciate their property's unique exposure and the steps that can improve resilience.

Research from the Insurance Institute for Business & Home Safety (IBHS) has shown that wind-driven embers are responsible for the majority of home ignitions during wildfires and can travel well ahead of the main fire front. Meanwhile, CAL FIRE identifies embers, radiant heat and direct flame contact as the three primary ways wildfires ignite homes, underscoring why conditions at the property level matter.

"People often think wildfire risk is simply a matter of whether a home is close to a fire, but the science is much more nuanced," said Steve Bennett, Senior Director of Climate Science and Catastrophe Modeling at Mercury Insurance. "Wind patterns, terrain, vegetation and the way a home is built all interact to influence how a wildfire behaves at a particular location. That's why two homes in the same neighborhood can experience very different levels of exposure during the same event."

Five reasons wildfire risk can differ from one home to the next

1. Wind patterns can change dramatically over short distances

Wind is one of the most important drivers of wildfire behavior, but it rarely moves uniformly across a landscape. Ridges can accelerate winds, canyons can funnel them and changes in terrain can create turbulent air currents that redirect embers toward one group of homes while largely bypassing another.

2. Topography influences how fires spread

Slope affects both the speed and intensity of a wildfire. Fires generally spread more rapidly uphill because flames preheat vegetation above them. Ridgelines, drainages and natural terrain features also influence where fire concentrates its energy and how embers are transported.

3. Embers often pose the greatest threat to homes

One of the biggest misconceptions about wildfire is that flames must reach a home for it to ignite.

IBHS research has found that wind-driven embers are the leading cause of home ignitions during wildfires. Carried by strong winds, embers can enter attic vents, accumulate in gutters, ignite combustible landscaping or lodge beneath decks long before the main fire front arrives.

4. Construction details matter

A home's vulnerability depends on much more than its address.

Roof materials, vents, windows, decks, fencing, attached structures and the five-foot zone immediately surrounding the home all influence how well a structure withstands ember exposure, radiant heat and direct flame contact. CAL FIRE's home hardening recommendations focus on strengthening these areas to reduce the likelihood of ignition.

5. Every property has its own wildfire risk profile

Wildfire risk is not determined by a single factor. Instead, it is shaped by the interaction of weather, fuels, topography, surrounding development and the characteristics of an individual home.

While no property can be made wildfire-proof, understanding how these variables work together can help homeowners make informed decisions that improve resilience before wildfire season reaches their community.

"Every property has its own wildfire profile," Bennett said. "No two homes experience identical conditions during a wildfire because the environment around each home is different. While no strategy can eliminate risk, understanding the science behind wildfire behavior helps homeowners better understand their exposure and identify practical steps that can improve resilience."

For information about wildfire safety and protection, visit the Mercury Insurance Resource Center.

About Mercury Insurance

Mercury Insurance (NYSE/NYSE TX: MCY) is a multiple-line insurance carrier predominantly offering personal auto, homeowners, renters and commercial insurance through a network of independent agents in Arizona, California, Georgia, Illinois, Nevada, New Jersey, New York, Oklahoma, Texas and Virginia, as well as auto insurance in Florida. Mercury writes other lines of insurance in various states, including commercial, business owners and business auto, landlord, home-sharing, ride-hailing and mechanical protection insurance.

Since 1962, Mercury has provided customers with tremendous value for their insurance dollar by pairing ultra-competitive rates with excellent customer service, through more than 4,200 employees and a network of more than 6,340 independent agents in 11 states. Mercury has earned an "A" rating from A.M. Best, as well as "Best Auto Insurance Company" designations from Forbes and Insure.com. For more information visit www.MercuryInsurance.com or follow the company on LinkedIn, Instagram or Facebook.

Media interested in receiving updates from Mercury can learn more at the Mercury Newsroom.

SOURCE Mercury Insurance